Bellatrix actually attended, so that Narcissa would have her needed escort. They arrived together and Bellatrix wore a black and cream dress. She was polite, if rather distant to most of the other society women although she was sure to offer her congratulations to Madeline and her commendations to Evangeline for hosting the event.
She declined to participate in most of the games, although when asked to give advice to Madeline, she raised an eyebrow, took a sip of her drink to take a moment and discard the myriad of inappropriate responses that immediately came to mind and then finally replied, "Always have make up sex after a fight." (Really, it was actually more appropriate than most of the other responses that she thought of!)